3com 8807 User Guide

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BGP/MPLS VPN Configuration
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Figure 132   OSPF multi-instance application in MPLS/BGP VPN PE
Figure 133   Multi-VPN-instance CE application in conventional LAN
Introduction to 
Multi-Role Host
The VPN attribute of the packets from a CE to its PE lies on the VPN bound with 
the ingress interface. This, in fact determines that all the CEs forwarded by the PE 
through the same ingress interface belong to the same VPN; but in actual network 
environments, a CE may need to access multiple VPNs through one physical 
interface. Though you can configure different logical interfaces to meet this need, 
this compromised method brings additional configuration burden and has 
limitation in actual use.
To resolve this problem, the idea of multi-role host is generated. Specifically to say, 
this idea is to differentiate the accesses to different VPNs through configuring 
policy routing based on IP addresses, and transmit downstream data flow from PE 
to CE by configuring static routing. The static routing under multi-role host 
circumstance is different from common hosts; it is implemented by specifying an 
interface of another VPN as the egress interface through a static route in a VPN; 
and thus allowing one logical interface to access multiple VPNs.
BGP/MPLS VPN 
Configuration
Configuring Various 
Kinds of Routers
Implementing BGP/MPLS VPN functions requires the following procedures in 
general: Configure basic information on PE, CE and P; establish the logical or 
MPLS  VPN  Backbone
VPN -RED
Site1
OSPF Area0
931*5((1
6LWH
263)$UHD
931*5((1
6LWH
263)$UHD
9315('
6LWH
263)$UHD
Area 2
OSPF 100 VPN-GREEN
Area 0
OSPF 100  VPN
OSPF 200 VPN GREEN
Area 1
CE11
CE12
CE31
CE22
PE1
PE2
PE3
Area 0
OSPF 100 VPN -RED
OSPF 200 VPN -GREEN
Area 1
MPLS  VPN  Bac kbone
VPN -RED
Site1
OSPF Area0
VPN
GREEN
Site1
OSPF Area1
VPNGREEN
Site2
OSPF Area2
VPNRED
Site2
OSPF Area1
-
CE21
RED
-
MPLS  VPN  Backbone
VPN -RED
Site1
OSPF Area0
931*5((1
6LWH
263)$UHD
931*5((1
6LWH
263)$UHD
9315('
6LWH
263)$UHD
Area 2
OSPF 100 VPN-GREEN
Area 0
OSPF 100  VPN
OSPF 200 VPN GREEN
Area 1
CE11
CE12
CE31
CE22
PE1
PE2
PE3
Area 0
OSPF 100 VPN -RED
OSPF 200 VPN -GREEN
Area 1
MPLS  VPN  Bac kbone
VPN -RED
Site1
OSPF Area0
VPN
GREEN
Site1
OSPF Area1
VPNGREEN
Site2
OSPF Area2
VPNRED
Site2
OSPF Area1
-
CE21
RED
-
MPLS Network
PE
R&D
Finances
Engineering
Multi-VPN-Instance CE
ospf 100
opsf 200
vpn-rd
ospf 300
vpn-finances
ospf 100
vpn-engineering
ospf 300
vpn-finances
opsf 200
vpn-rd
vpn-engineering
MPLS Network
PE
R&D
Finances
Engineering
Multi-VPN-Instance CE
ospf 100
opsf 200
vpn-rd
ospf 300
vpn-finances
ospf 100
vpn-engineering
ospf 300
vpn-finances
opsf 200
vpn-rd
vpn-engineering